Embodiments described herein generally relate to ultrasound imaging systems, and more particularly to displaying information using ultrasound imaging systems, such as shear-wave elastography images and strain elastography images.
Ultrasound elasticity imaging is an elastography imaging modality that employs ultrasound waves to probe the mechanical properties of biological tissues and produce corresponding images. Ultrasound elasticity imaging can be subdivided into two types: strain elastography imaging (SEI) and shear-wave elastography imaging (SWEI), each having different advantages. For example, SEI has a higher sensitivity than SWEI, however, SWEI has a higher specificity than SEI.
SEI is a qualitative technique based on measuring differences in compression displacement of the tissue by applying deformation or compression to a region of interest from an external or patient source. Changes in tissue stiffness, such as an organ, may be an indicator of disease. Accordingly, measuring tissue stiffness allows a physician to identify or detect liver fibrosis and cirrhosis, prostate cancer, breast cancer, and the like. For example, a portion of the tissue may be stiffer than surrounding tissues indicating an onset or presence of a disease such as cancer, tumor, fibrosis, steatosis, or other such conditions.
SWEI is based on applying acoustically generated shear-waves to determine mechanical properties of the tissue, usually measured as a velocity, by tracking the displacement of the tissue at a plurality of points caused by the shear-wave over time. The velocity relates to one or more mechanical properties of the tissue and may provide stiffness information measured in, for example, kilo Pascals (kPa). For example, a normal glandular measured from a patient is approximately 57 kPa, alternatively, a ductal tumor or breast cancer is approximately 301 kPa.
Ultrasound imaging systems are known that can display different ultrasound images. However, these known systems cannot display SEI and SWEI frame images concurrently or as an overlay of SEI on top of SWEU or vice versa. Further, these systems are not able to concurrently display the SEI images while acquiring the SWEI image frames (or vice versa) concurrently. Due to the different information provided by and the differing advantages of SEI and SWEI, a need exists for an ultrasound imaging system able to display the SEI and SWEI images concurrently.